Iran's Supreme Leader Ayatollah Ali Khamenei has accused the U.S. and Israeli intelligence services of the involvement in the killing of an Iranian nuclear scientist, the official IRNA news agency reported.

Mostafa Ahmadi Roshan, a deputy director of Iran’s largest uranium enrichment plant, died in a car bomb explosion in Tehran on Wednesday. Local police sources said a motorcyclist attached a magnetic mine to his car.

"This cowardly murder, perpetrated by those who do not dare claim their abominable crime by accepting the responsibility, was committed like the other crimes with the planning or support of the intelligence services of the CIA and Mossad," Khamenei said in a message of condolences to Roshan’s family on Thursday.

“Such criminal acts show that the Imperialism and global arrogance headed by the US and international Zionism have come to a dead-end in their confrontation with the determined and pioneer Iranian nation,” he said.